Example of three projects devoted to water resource

assessment

in Developing Countries

- GASPAL (Groundwater as Paleo indicator (EEC, 97-2000):

Network for Data base in West Africa, for groundwater

geochemistry and isotope compositions, and a booklet for

communication with Policy makers

- MAWARI (French Foreign Ministry): Shared research in the East

African rift (2005-2010)

- G-WADI - UNESCO’s program for Water and Development

Information for Arid Lands.

GROUNDWATER: A RENEWABLE

RESOURCE?

What can geochemical and isotopic information

contained in groundwater tell us about its age

and origins as a basis for sound management?

Focus on Sahara and Sahel

SOME SUGGESTIONS AND

RECOMMENDATIONS

Reliable databases are needed on physical and

chemical properties of each basin/region.

Monitoring programmes are needed, for both

quantityand quality; use of isotopic tools is

desirable to confirm if modern recharge or

palaeowater is being used.

The solutions to problems may be different in

‘rich’ countries as compared with ‘poorer’

countries.

Balanced resources management is needed not

crisis management.

Conservation measures may need to be

implemented with the avoidance of wasteful

practices, especially the use of palaeowater for

irrigation.

Sustainable Groundwater Management in the East African Rift

the MAWARI Partnership: Djibouti - Ethiopia – France - Kenya

A joint initiative to set up a south – south regional network of African

Geoscientists whose main objectives are to :

• Develop educational and scientific regional geo-capacity

• Boost EAR knowledge thanks to acquisition of multidisciplinary data and

valorization of existing works

• Involve all levels of participation : students (MSc, PhDs,) professors,

professionals and water authorities

• Strengthen the regional partnership of water actors

• Promote regional institutional management of the Rift GWR

• Associate future participants from neighboring countries

• Increase participation in scientific north – south Projects :

DJIBOUTI

ETHIOPIA

KENYA

Sustainable Management of Water

Resources in the East African Rift System

MAWARI PROJECT Scientific and Consultative

Committee Meetings, Poitiers, France, 27th – 31st May, 2008

“Vulnerability of Groundwater to Pollution in the Kenya Rift – Progress Report”

by

Prof. Justus Barongo

MAWARI-ETHIOPIA TRANSECT PROJECT

PROGRESS REPORT V

(December 2008 - May 2008)

CERD

Fluoride MAWARI Project ETHIOPIA

Origin, Genesis and Distribution of Fluoride in the Ethiopian Rift

and

Development of Defluoridation Technologies

May 27-30, 2008

Poitiers, France

Berhanu Gizaw, PhD

G-WADI

- A GLOBAL NETWORK-

UNESCO IHP-VI

UNESCO’s program for Water and Development Information for Arid

Lands.

Successful G-WADI initiatives to date have been primarily scientific.

The transfer of technology and science is the prime target of G-WADI

communicate research outcomes with policy makers, water managers and

those involved in education, capacity building and social programmes is

also important.

To this end a capacity building activity is being launched, based on

countries that have the potential to be the nucleus of a G-WADI network in

SSA.

PROTECTION DES EAUX SOUTERRAINES EN AFRIQUE SUB

SAHARIENNE. NECESSITE DE PRENDRE EN COMPTE DES

SIGNAUX CARACTERISTIQUES INDICATIFS ET D’ALERTE, ET UN

MONITORING ADAPTE

GROUNDWATER PROTECTION IN SUB SAHARIAN AFRICA.

NEED TO TAKE INTO ACCOUNT INDICATIVE AND WARNING

SIGNALS, ADEQUATE MONITORING

C. Leduc, Y. Travi

G-WADI

Some examples of dysfunctioning Science/ Policy

• Pb of administrative structure vs Hydrological units. Ex. Merguellil Basin, Tunisia.

• Komadugu/Yobe and Logone planning without a full knowledge of Hydrological conditions

• Piezometric and nitrate contents evolution in the Iullemeden shallow aquifers. Basic monitoring needed

• Nubian sandstone overexploitation? High pumping before any serious studies and modeling

• Traditional défluoruration programs without taking in account the chemical specificities of groundwater to be treated

Administrative Limits vs Hydrological Units

Several regions covering the same catchment or aquifer

Sometimes different objective and policy

Also different databases, .

Example of Merguellil basin

2 governorates, several

delegations

No link with hydrological

systems

Tunisie

Juxtaposition of different departments

Sometimes; A risk of lack in cooperation

contradictory policies

ex. Tunisia : Agriculture Ministry, in charge of most of water management aspects,

but each service (DG) has its autonomy

DG ACTA, soils and

water preservation DG RE, water ressources

(surface+underground)

DG BGTH, big dams

We must also consider that time scales for administrative management

is often different from needed time for scientific analyses

Evolution des surfaces couvertes par les

aménagements de conservation des eaux et

sols

Erosion protection induce a

strong decrease in run off at the

exit of the catchment

The main part of

the flow is

currently coming

from the upper

part peu

aménagé

As a result, a lot of

unwanted consequences

El Haouareb dam often

completely dry :

- Due to important leakage

(>50%) through fractures in

lime stones

- It is not longer able to

provide water for irrigation

perimeters

The planned management for usual dam (keeping some water for irrigation) have a

negative effect in this context (evaporation loss))

Only 20 years after dam

building alternative solutions

begin to be thought.

retenue de 90 Mm3

Example of Iullemeden Basin (SW Niger)

a rise in the water-table has been observed even

during the decades of severe drought (70s, 80s)

it results from the replacement of natural vegetation

by millet fields and fallow

the groundwater recharge has been multiplied by 10

(from 2-5 mm/yr to 25-50 mm/yr)

mean rise in the water-table (m/year)

Iullemeden Basin (SW Niger)

the extension of millet fields results in:

an increase in the number of temporary ponds,

a larger extent and a longer duration of these ponds,

(which may lead to health problems as outbreak of Plasmodium)

a deterioration in the groundwater quality (without any input of artificial

fertilizer)

0

1

2

3

0

1

2

3

NO3-

far away fromponds

close to theponds

Iullemeden Basin(SW Niger) :

• The 10-fold increase in groundwater recharge could not really help in

developing large irrigation schemes (which is not at all in the villagers habits)

• The precise identification of physical processes involved in the environmental

change enables a reliable forecast of the regional future state

For benefiting from these results an adequate monitoring is

needed

Example of Chad Lake and wetlands mistreated:

- les barrages sur l'amont de la Komadougou Yobé réduisent considérablement

ses zones humides (ex les Hadejia-Nguru wetlands, sorte de delta intérieur de 2000

km2). Antérieurement, il y avait recharge de la nappe phréatique (variation

saisonnière de 1 à 3 m), qui n'existe plus.

- l'endiguement du Logone a supprimé l'essentiel des crues dans les Yaérés

(environ 8000 km2). La recharge de la nappe est plus incertaine ici mais personne

ne l'a considérée avant réalisation des travaux. On est en train de détruire

partiellement pour revenir à un état antérieur

Dans ces deux cas, il y a

eu à la fois

- un très lourd problème

environnemental

- un impact hydrologique

complexe

-30

-31

-32

01/07/95 01/07/97

-15

-16

-17

01/07/95 01/07/97

Instrumentation problem

Space and time step difficult to define

These two points, 5 km far represent the same aquifer (CT du sud-ouest du

Niger) in the same environmental conditions.One the right, one measure by

year could be enough. On the left, one measure each 15 days in rainy season

is needed for identifying all the aquifer functioning.

These 2 points on the same aquifer (CT in the South West Niger) show:

- Strong inter annual variability typically from semi-arid zones

- Several superposed dynamics corresponding to to several very different time scales (Seasonal+ some years + pluri decennal)

-9

-8

-7

1/1/81 1/1/85 1/1/89 1/1/93 1/1/97

superposition de 3 dynamiques 1/8/91 1/8/93 1/8/95 1/8/97 1/8/99

-20

-18

-16

-14

Intensively

exploited. Great

man made river

project

Nubian Sandstone

Aquifer

Lake Kufrah

Source: National Geographic Magazine,

Vol 46 (3), September 1924

The lake, sustained by

groundwater, in the

past, is currently dry.

The great man made

river project started

before full study, in

progess at the present

time (transboundary

programs)

Over Exploitation?

Some traditional Fluoride Removal Methods

Removal Methods Capacity/

Dose

Efficiency

(%)

Advantages Disadvantages Relative Cost

Precipitation

Alum 150mg/mg F 80 Established

Process

Sludge produced,

treated water is acidic,

residual Al present

Medium - high

Lime 30mg/mg F 30-70 Established

Process

Sludge produced,

treated water is alkaline

Medium - high

Nalgonda 150mg alum +

7mg lime/ mg

F

95 Low-tech

established

process

Sludge produced, high

chemical dose, residual

Al present

Medium - high

Gypsum + fluorite 5mg gypsum

+ <2 mg

fluorite/mg F

70 simple Requires trained

operators Low

efficiency, high

residual Ca, So4

Low - Medium

Adsorption / ion exchange

Activated Carbon Variable 96 - Large pH change

before and after

treatment

High

Clay pots 80mg F/kg 60 Locally

available

Low capacity, slow low

Activated alumina 1200 g F/m3 96 Effective, well

established

Needs trained

operators, chemicals

not always available

Medium

Bone char 1000 g F/m3 97 Locally

available,

High capacity

Not universally

accepted

low

IOCS (Iron Oxide coasted sands) and Natural Iron Enriched

Adsorbents as an Alternative Low-Cost Defluoridation

Technique in Rift Valley of Ethiopia

Esayas Alemayehu

Jimma University, Jimma, Ethiopia

From :

MAWARI Fluoride project - Development of Defluoridation Technologies

Below is an example showing the necessity to adapt the method,

considerind the quality of the water to be treated, and if possible

to modelize the chemical process

Currently a lot of experiments, conducted without scientific base, are founded

Selected Results

iii. Effect of pH

• For fluoride there was a significant increase in removal when the pH decreased. With an increase in pH from 2 to 10, fluoride removal decreased from 77% to 15%.

• This is possibly because of complex aqueous chemistry of fluoride.

• Previous research indicated that at a pH < 7, the iron oxide coated sand is positively charged.

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0 2 4 6 8 10 12

pHF

ad

so

rbed

(m

g/g

)

Figure: Effect of pH on F removal by IOCS (initial F concentration 5 mg/l, adsorbent dosage 8 mg/l, and contact time 72 hours, pH range: 2-10)

It was concluded that using IOCS, the fluoride removal capacity was more favorable with pH lower than 6. Since it is impractical to work with lower pH, more experiments will be performed using higher pH (e. g. pH > 6.8) which is the value for most of ground water.

The main objective of this talk is to initiate a discussion

with the goal to help identifying and listing different

scientific problems and the reasons of a bad use of

scientific results in water policy.

Some guides, based on scientific knowledge, pointing

out minimum preliminary observations, warning signals

and adequate monitoring would be proposed to policy

makers.

I think a good way would be to produce a G-WADI

brochure/ training leaflet